1. Technical Field
The present invention pertains to internal combustion four-stroke piston rotary engines under classes: 123/41.4, 48, 80R, 190A, 204, 222, 225–231, 237–239, 241, 243, 244, 249 and 418/136, 246, 249 by the U.S. Patent Classification Definitions and F02B 053/00-06 by the International Classification.
Related documents: Michael J. Moran & Howard N. Shapiro. “Fundamentals of Engineering Thermodynamics”. 1988; “Basic Thermodynamics: Elements of energy Systems” Skrotzki, 1963; “Diesel and high compression gas engines” 3rd edition, Edgar J. Kates & William E. Luck, 1974.
2. Description of Prior Art
There are three main types of prior art internal combustion engines (ICE) that are discussed here:
Conventional Reciprocating Engines (RE);
Gas Turbine (GT);
Combined Piston Rotary Engine (COMBINED PRE).
RE: The first Otto and Diesel REs had 4–6%, recent ones have 35–45% efficiency, and that is a dead end. The limitation cannot be surmounted in principle, only small additions for a great expense. In reality, 12–16 valves, new oils, fuel & fuelling add price rather than efficiency. Objective necessity to find progressive substitute have ripened, but no alternative yet.
Mean while, technology and science experience is growing. The knowledge of rich RE's HERITAGE helps to form main principles of future ICE engine.
The partial analysis of the heritage is given below:    1. In RE pressure and volume of CH vary following the piston movement. As a result the speed of burning lowers from “burst” until “kerosene lamp”; combustion is not full. Limited by danger of a back blow Advance of an Ignition gives limited effect. Idea introduced in U.S. Pat. No. 5,010,860 is good, but drawback is too big 720 degrees of Advance of an Ignition. The optimal diapason is much less.Conditions of durability and sealing stipulate limited initial air pressure. In result speed of burning is low, and combustion is not full.
CONCLUSION: for the best burning, volume of CH must be constant and independent of piston movement; air pressure must be at its possible high; time for combustion must be optimized.    2. In RE the same cylinder gives room for suction, burning and expansion, combustion materials retain in the cylinder and burning fresh air-fuel mixture is not efficient.
CONCLUCION: stroke spaces have to be separated to perform only specific function: sucking, expansion and combustion and CH has to be cleaned up before fresh air charge.    3. In RE compression and expansion take place in the same volume, and gas energy is utilized incompletely: thus high-energy gas exhausts out with harm materials and high sound.
CONCLUSION: for higher efficiency, compression and expansion volumes have to be different with ratio Rv=Vt/Vc>1, where Vt—volume of expansion; Vc—volume of compression.    4. RE cannot be adapted for effective operational optimization of nominal power; throttling doesn't solve the task: specific fuel consumption is higher then in optimal regime. The problem may be solved by way of displacement volume regulation, what is problematic in RE.
For instance: in case of an automobile, higher power of all cylinders is needed in short-term periods (5% of operational time). Other time customer pays extra money for “store” of the power with its inevitable extra fuel consumption.
The regulation will allow obtaining new optima engine to secure only “demand” power for overcoming friction and aerodynamic resistance instead of idle “Work for himself”.
Additionally, launching of engine with operatively reduced displacement volume in some outward conditions is much lightly then with a big one.
CONCLUSION: for fuel economy and lighten of launching would be useful an adaptation of an engine for operational displacement volume regulation by turning off & on part of the engine cylinders.    5. RE practice shows that cylinder-piston pair is a sufficient combination to get high ratio compression and expansion if there is no stray air volume in cylinder, but complex crankshaft structure and imperfect valve mechanism with rocker-spring drive and penetration valves into cylinder confine full possibilities of a said pair.
For RE rotary valves idea is good (U.S. Pat. No. 4,381,737; U.S. Pat. No. 6,321,699 and other under class 123/41.4, 80R, 190A) but it solves a partial problem, not in complex, and didn't take roots.
CONCLUSION: there is preferably to use piston-cylinder pair with simplified shaft and valves drive, both on rotary base and without extra stray air volumes in cylinders.    6. For more than 100 years of RE experience main principles of ICE and its function components were defined. In result many of the most reliable and functionally fit systems and elements have obtained standardized principles of design and operation.
CONCLUSION: it is preferable to use standardized elements of RE adapted for new work conditions in new engines.    7. Today RE with its huge assortment dominates in autonomic power applications.
CONCLUSION: new engine must have no less then RE assortment.
SUMMARY CONCLUSION: to satisfy contemporary market substitute of RE must possess higher efficiency, must be simpler, smaller in size, more reliable and cheaper, must be adapted for optimization of nominal power by displacement volume regulation for fuel economy and better launching, must be built on piston-cylinder principle with a high compression ratio, must have expansion volume exceed the compression one and to allow no less then RE assortment.
GT: There is a rotary ICE with practical history for about 60 years. In comparison with RE design GT is much simpler, torque is bigger and more uniform; scheme is built of separate C, T, CH, and efficiency is more.
Nevertheless, GT is a vane, not a piston machine and cannot reach high compression ratio; GT has limit diapason of work regimes under conditions of vanes' profile. Therefore, GT generally is in use for objects with predominantly stationary work regime, they are noisy, expansive, and cannot compete with RE by size.
CONCLUSION: the substitute of RE preferably has to repeat a design of GT as a rotary engine with separate elements C, T and CH for higher efficiency, but retain piston-cylinder principle for higher compression—expansion ratios.
There is a class of engines comprising elements of GT and RE and plenty of speculative ideas; first Piston Rotary Engines were published simultaneously with first RE, but until now not one rotary engine was built as alternative to RE by the following reasons:    Inventions solve partial task often for the sake of originality instead of simplicity (U.S. Pat. No. 6,276,329 there are too complex drive of the partition and great stray air volumes in cycle strokes; U.S. Pat. No. 6,298,821, good idea was not logically completed);    Many inventions have complex design of rotors comprising additional movable elements: U.S. Pat. No. 6,688,276 B2, U.S. Pat. No. 6,247,443 having staggered pivoted elements, sliding vanes or mounted on rotors). Drawbacks of the inventions are the following:    Complex design leading to low reliability and operational inconvenience;    Typical drawbacks of REs where the same cylinder consequently performs all cycle strokes;    Cannot be reached fullness of combustion, Principle of Advance of an Ignition (AI) cannot be used, U.S. Pat. No. 6,276,329 with separated Combustion Chamber (CH) doesn't solve the problem.    Not one invention solves problem of cleaning of the CH.
An overcoming of all the drawbacks is possible in COMBINED PRE built on principle of GT: there is scheme with separate C, T and CH, but only a few inventors mark importance of it: (U.S. Pat. No. 6,298,821 B1 apart from CH; U.S. Pat. No. 6,606,973 B2: separate C and T; U.S. Pat. No. 4,909,208: CH combined with valve mechanism, There are good ideas but bad lacks under pp 1, 2, 4, 6 of RE HERITAGE);
CONCLUSION: COMBINED PRE with separate C, T and CH is the best substitute of RE.
Complex idea of such substitute for the first time is given in KE.